Dermatology Flashcards
differentiating vitiligo from pityriasis versicolor?
Vitiligo-depigmentation
Pityriasis versicolor-hypopigmentation
What is erythema multiforme major?
Erythema multiforme is an acute, immune-mediated skin condition that typically presents with target-like lesions on the skin and mucous membranes (eyes and mouth). This condition can be triggered by infections (commonly herpes simplex virus or mycoplasma pneumoniae) or medications.
Describe seborrhoeic dermatitis?
Seborrhoeic dermatitis in adults is a chronic dermatitis thought to be caused by an inflammatory reaction related to a proliferation of a normal skin inhabitant, a fungus called Malassezia furfur (formerly known as Pityrosporum ovale).
Causes itchy rash affecting the head : scalp (may cause dandruff), periorbital, auricular and nasolabial foldsdistribution is commonly caused by seborrhoeic dermatitis, causes ill-defined, pink coloured patches with a yellow/brown scale.
If untreated can lead to blepharitis and otitis externa
the first-line treatment is ketoconazole 2% shampoo
AKA as cradle cap in children - not normally itchy for them
What is the management of psoriasis?
regular emollients always
first-line:
steroid + vit D analogue (separate) OD
second-line: no improvement after 8 weeks - vitamin D analogue BD
third-line: if no improvement after 8-12 weeks then offer either: a potent corticosteroid twice daily for up to 4 weeks, or a coal tar preparation applied once or twice daily
In secondary care: phototherapy, biological agents
Topical Vit D (calcipotriol) can be used for long term mx of psoriasis if needed
How do you treat Pityriasis versicolor? what causes it?
topical antifungal.- ketoconazole shampoo/ selenium sulphide shampoo/ top imidazole cream
melassezia furfur
Superifical spreading vs nodular vs lentigo vs acral melanoma types?
superficial: most common, typically flat patch of pigmented skin which grows slowly. It can be recognised by an ABCDE approach. Younger people.
Nodular: 2nd most common. Older people. Red or black lump or lump which bleeds or oozes
Lentigo:elderly, slow growing
Acral: Nails, palms or soles, People with darker skin pigmentation. Hutchinsons sign (nail)
What is the name of the rash that appears in lyme disease?
Erythema chronicum migrans (‘bulls-eye’) rash occurs in around 80% of patients with Lyme disease
What is the mx of acne?
Mild: combination of two: topical abx (clina/ erythro) +/- topical benzoyl peroxide +/- topical retinoid (tretinoin, adapalene)
moderate to severe acne:
Topical retinoid/ benzoyl peroxide/ azelaic acid + PO abx (doxy) or COCP for women
Topical and oral antibiotics should not be used in combination!!!
severe acne: extensive inflammatory lesions, which may include nodules, pitting, and scarring
oral isotretinoin: started by specialists only
What rashes are associated with reactive arthiritis?
How is reactive arthirtis mx?
circinate balanitis (painless vesicles on the coronal margin of the prepuce)
keratoderma blenorrhagica (waxy yellow/brown papules on palms and soles)
NSAIDS
sulfasalazine and methotrexate are sometimes used for persistent disease
What is Pityriasis rosea
May be proceded by viral infection
herald patch (usually on trunk)
followed by erythematous, oval, scaly patches which follow a characteristic distribution with the longitudinal diameters of the oval lesions running parallel to the line of Langer. This may produce a ‘fir-tree’ appearance
Mx of rosacea?
mild-to-moderate papules and/or pustules:
topical ivermectin 1st line
alternatives include: topical metronidazole or topical azelaic acid
moderate-to-severe papules and/or pustules:
topical ivermectin + oral doxycycline
Steroids are CI!!! can make worse
describe a dermatofibroma?
common, benign, fibrous nodule. Well defined, symmetrical, one colour.
dimple sign = dimples when it is pinched
may form in relation to trauma such as insect bites.
These lesions are often asymptomatic but may be associated with mild pain or itch.
How do you differentiate between bullous pemphigoid or pemphigus vulgaris?
Both blisters/bullae
Tense blisters (deeper location) no mucosal involvement: bullous pemphigoid (avOID = NO mucosa)
flaccid blisters + mucosal involvement: pemphigus vulgaris (US = includes mucosa)
What condition causes hair loss in localised regions with no scarring/ itching?
Alopecia areata
Features of rosacea?
flushing of nose/ cheek/ forehead, pustules, Rhinophyma (bulbous nose), blepharitis, telangectasia
NOT itchy
What rash is associated with coeliacs?
Dermatitis herpetiformis
itchy, vesicular skin lesions on the extensor surfaces
tinea corporis vs erythema multiforme
tinea has single well-demarcated, erythematous circular patch with a raised edge and central hypopigmentation. Caused by fungal infections eg trichophyton, microsporum, epidermophyton
Erythrema multiforme has multiple separate spreading rings and usuallys viral cause/ drug cause, target lesion, mucosal involvement
vs SJS vs Toxic epidermal necrolysis (TEN) vs Staphylococcal Scalded Skin syndrome (SSSS)
TEN:
>30% body surface
Often triggered by meds eg anti-epileptics, abx, allopurinol, NSAIDs
extensive detachment of the epidermis, leading to the formation of large fluid-filled blisters that easily separate upon pressure. (+ve nikolskys)
Can cause AKI
SJS
<10% body area, like TEN but less severe
SSSS:
Mostly children.
Not drug cause
How urgently should you refer a BCC?
routine UNLESS eyes/ nose where further damage may occur
What is the hutchinsons sign in shingles?
herpes zoster: This is Hutchinson’s sign which is strongly predictive for ocular involvement - nasociliary pathway of trigeminal nerve (can lead to anterior uveitis). rash @ tip of nose
Mx of keloid scars?
early keloids may be treated with intra-lesional steroids e.g. triamcinolone
What is pompholyx eczema?
Pompholyx, also known as dyshidrotic eczema, usually presents with small fluid-filled blisters/ vesicles on the palms of hands or soles of feet –> dry sesquamating phase
Flares up in heat/ humidity
What causes Kaposis sarcoma?
Human herpes virus 8
What is necrobiosis lipoidica?
Middle aged women with diabetes typically
bilateral erythematous plaques on shin with telangectasia
Yellow hue due to lipids deposition
may be asx/ itchy/ tender
